WorksheetsFinal Exam Reviewer
Total questions: 45
Worksheet time: 23mins
The synthesis of urea from ammonium cyanate.
was a critical component of the Miller-Urey experiment.
requires a protein as a catalyst
helped dispel the vital force theory
supported the vital force theory
Which of the following best describes the results of the Miller-Urey experiment
It proved that DNA is the genetic material
It produces proteins under conditions simulating the early Earth.
It created living cells from non-living materials.
It produced some simple organic compounds from a mixture of gases presumed to have existed in the early atmosphere.
All of these results of the Miller-Urey experiment.
Which of these kingdoms includes only prokaryotic organisms?
Animals
Fungi
Monera
Plants
Protista
Which of the following classes of compounds is hydrophilic?
Sugars
Fatty acids
Amino Acids
Sugars and amino acids
All of these
For an endothermic reaction to be spontaneous, which of the following must be true?
heat must be given off by the reaction
energy must be added to the reaction
the temperature must be very low
the entropy must increase substantially
none of the above are true
Which of the following has no L or D configuration
Glyceraldehyde
Proline
Glycine
All of these have an L or D configuration
The amino acids which occur in proteins
are all of the L-form.
Are all of the D-form
can be either the L- or D-form.
do not have L- and D- forms.
Which of the peptides would absorb light at 280 nm? Ala-Lys-His
Ser-Gly-Asn
Ala-Ala-Trp
Val-Pro-Leu
Ser-Val-Ile
The intrinsic properties of the 20 amino acids include all EXCEPT:
a-Carbon is symmetric.
The capacity to polymerize.
Novel acid-base properties.
Varied structure and chemical functionality in side chains.
Chirality
Which of the following best describes the structure of collagen
It is composed of a single a-helix.
It is a double helix
It is a triple helix
It is composed primarily of B-sheet.
Which of the following is often found connecting the strands of an antiparallel B-sheet?
B-bulge
reverse turn
a-helix
prosthetic group
The type of bonding labeled “L” in these figure is
Hydrogen bonding of the peptide backbone
Hydrogen bonding involving the R-groups
Hydrophobic interactions
Metal ion coordination
Electrostatic attraction
Amino acid side chains capable of forming hydrogen bonds are usually located on the protein _____ and form hydrogen bonds primarily with the _______.
surface, water solvent
interior, water solvent
surface, other amino acid side chains
interior, other amino acid side chains
all are true
Electrostatic interactions among amino acids residues on proteins may be damped out by high concentrations of:
water
organic solvents
salts
heat
all of the above
_____ between tightly packed amino acid side chains in the interior of the protein are a major contribution to protein structure.
Hydrogen bonds
Electrostatic interactions
Covalent ester bonds
Van der Waals interactions
All are true
Secondary and higher orders of structure are determined by all EXCEPT:
hydrophobic interactions (tertiary structure)
ionic bonds (tertiary structure)
van der Waals forces (tertiary structure)
hydrogen bonds (secondary structure)
peptide bonds (primary structure)
Which of the following items was one of the crucial elements of the Anfinsen experiment with ribonuclease A?
hydrophobic interactions were disrupted by the addition of B-mercaptoethanol
correct formation of disulfide bonds was achieved even with urea present
removal of B-mercaptoethanol resulted in complete denaturation of the protein
the presence of 8 cysteine residues means that there are 105 different disulfide bonds possibilities
none of the above
Hemoglobin is an a2,b2____ whereas, glutamine synthetase from E. coli is an a12______.
-homodimer, -homomultimer
-heteromultimer, -homomultimer
-homomultimer, -heterodimer
-heterodimer, -monomeric protein
-heterodimer, -homomultimer
The Bohr effect for oxygen binding states that
Mb binds oxygen more tightly than Hb.
Hb will bind oxygen very tightly when the CO2 concentration is high.
as the pH goes down, Hb binds oxygen less tightly.
Hb’s ability to bind oxygen increases with higher oxygen concentration.
Which of the following is true regarding effectors of oxygen-hemoglobin binding?
actively metabolizing tissues produce acid which increases hemoglobin’s affinity for oxygen
the presence of CO2 enhances the release of oxygen from hemoglobin
2,3-bisphosphoglycerate must dissociate from hemoglobin before oxygen can be released
the presence of protons will counter the effect of CO2 on the release of oxygen by hemoglobin
none of the above
The oxygen binding curve of which of the following is the closest to that of myoglobin
hemoglobin at pH 6.8
hemoglobin that lacks BPG
maternal hemoglobin
fetal hemoglobin
Fetal hemoglobin (Hb F ) has an intrinsically greater affinity for O2 than adult hemoglobin (Hb A) because:
Hb F has a diminished capacity to bind BPG compared to Hb A.
Hb A has a greater affinity for oxygen than does Hb F.
BPG binds Hb F with greater affinity that it binds Hb A.
The pH of fetal blood is less than the pH of maternal blood.
All of the above are correct
Which of the following is not true?
In thermodynamics, spontaneous does not mean instantaneous or even fast
If a reaction is spontaneous then it has a negative deltaG.
Speed of a reaction is a kinetic parameter, not a thermodynamic one.
A reaction with a positive deltaG can never happen.
Given the rate law, rate = k[A][B], the overall reaction order is
zero
one
two
cannot be determined
In the induced-fit model of substrate binding to enzymes
the substrate changes its conformation to fit the active site
the active site changes its conformation to fit the substrate
there is a conformational change in the enzyme when the substrate binds
there is aggregation of several enzyme molecule when the substrate binds
The active site of an enzyme is the place where the following happens
The enzyme substrate complex forms here.
The catalytic reaction happens here.
Allosteric regulation of enzyme rate occurs here.
The enzyme-substrate complex forms and the reaction occurs at the active site.
All of these are correct.
Which of the following is true?
The E-S complex often dissociates with no reaction taking place.
The E-S complex must form before a reaction can take place
Once the E-S complex forms, it can go on to form product or dissociate to E + S
All of these are correct
Histones contain large amounts of which of the following amino acids?
histidine
glutamic acid
lysine
leucine
tryptophan
Which conclusion can be drawn from the experimental observation that a single strand of DNA contains 2100 A residues and 1800 T residues?
There must have been some loss of material in their extraction because the number of A and T residues must be the same.
This is a palindromic sequence.
There must be 2100 T and 1800 A residues on the complementary strand.
This must be prokaryotic DNA
None of these
Which of the following statements concerning transfer RNA is true?
It has the highest molecular weight of the commonly occuring forms of RNA.
It has no internal hydrogen bonding.
It bonds to amino acids in the course of protein synthesis.
It is the smallest of the RNA types
All of these are true.
Which of the following is not an activity of DNA Polymerase I?
Polymerase activity.
Ability to nick intact double stranded DNA.
5’ -> 3’ exonuclease.
3’ -> 5’ exonuclease
All of these are present in DNA Pol I.
RNA synthesis begins at the base in the DNA sequence designated by the following number:
+1 (plus one)
0 (zero)
-1 (minus one)
-10 region (minus ten)
It varies between genes
Which of the following is true concerning the first nucleotide incorporated into an RNA chain?
The first nucleotide incorporated into the RNA chain retains its 5‘- triphosphate
The first nucleotide is always GMP
The first nucleotide is always cleaved off post-transcriptionally
The first nucleotide is always modified after transcription
Where is the TATA box located?
At the transcription start site (+1)
-10
-25 region.
-40 region.
Which of the following is required for RNA splicing to occur?
a free 5’ hydroxyl created by hydrolysis of the phosphate ester bond
a cyclic phosphodiester at the 3’ end of the RNA molecule
a 2’ hydroxyl group
the enzyme splicase
none of the above
When lactose is absent, what happens to the lac repressor? (same answer to tryptophan)
It binds to the promoter.
It binds to the operator.
It is degraded.
It is activated by cAMP.
Which of the following best describes the assembly process to initiate translation in prokaryotes?
small ribosome subunit associates with large subunit; mRNA associates next; IFs bring in first f-Met-tRNA; bound NTP hydrolyzed.
IF binds f-Met-tRNA; small ribosome subunit associates next; mRNA associates next; then large subunit; bound NTP hydrolyzed.
IF w/ bound NTP binds f-Met-tRNA; mRNA associates next; small subunit associates next; bound NTP hydrolyzed; large subunit associates.
small subunit associates with mRNA; IF w/ bound NTP brings in first f-Met-tRNA; IF then hydrolyses bound NTP; large subunit associates
During elongation, tRNA binds initially to the
“A” site on the ribosome
”P” site on the ribosome
”E” site on the ribosome
Degradation of proteins
happens randomly
frequently makes use of proteasomes
always requires ubiquitination of proteins to be degraded
tends to target proteins with basic amino acid residues to their N-terminal ends
As a result of mutarotation, D-glucose exists in all of the following forms EXCEPT:
L-glucopyranose
a-anomer
free aldehyde
B-anomer
all are true
Diastereomers of D-glucose include all of these, except:
D-Fructose an isomer
L-Glucose an enantiomer
L-Idose
D-Galactose
Which statement correctly explains the structural and functional significance of glycosaminoglycans (GAGs)?
GAGs consist of repeating monosaccharide units with only hydroxyl functional groups, making them highly hydrophobic and ideal for lipid transport.
The presence of an amino sugar and a negatively charged sulfate or carboxylate group allows GAGs to attract water, providing lubrication and structural integrity in tissues.
Heparin functions as a blood coagulant by forming covalent cross-links between platelets, preventing excessive bleeding.
Hyaluronic acid is a highly branched glycosaminoglycan that forms rigid, insoluble structures in connective tissues.
Which of the following groups is not present in a cerebroside?
Sphingosine
Fatty Acid
Phosphate
Sugar
All of these can be components of cerebrosides
Which of the following best explains the mechanisms of aspirin’s anti-inflammatory effects?
It blocks leukotriene synthesis, preventing airway constriction.
It inhibits the cyclooxygenase (COX) enzyme, preventing prostaglandin synthesis.
It neutralizes thromboxane A2, reducing platelet aggregation.
It increases cholesterol synthesis, reducing membrane fluidity.
In the induced-fit model of substrate binding to enzymes
the substrate changes its conformation to fit the active site
the active site changes its conformation to fit the substrate
there is a conformational change in the enzyme when the substrate binds
